Microarray-based detection of Salmonella Enteritidis genes involved in chicken reproductive tract colonization

Salmonella Enteritidis has developed the potential to contaminate table eggs internally, by colonization of the chicken reproductive tract and internalization in the forming egg. The serotype Enteritidis has developed a mechanism to reside in this organ more successfully than other serotypes. Until now, the strategy exploited by Salmonella Enteritidis to do so remains largely unknown. For that reason, a microarray-based transposon library screen was used to identify genes which are essential for the persistence of Salmonella Enteritidis inside primary chicken oviduct cells ‘in vitro’ and inside the reproductive tract ‘in vivo’. In total, 81 genes were identified to be essential to persist in both the oviduct cells and the oviduct tissue. Major groups of importance include the Salmonella Pathogenicity Islands 1 and 2, genes involved in stress responses, cell wall and LPS structure and the Region Of Difference (ROD) genomic islands 9, 21 and 40